xviii INTRODUCTION government had become illegitimate. Fears arose about government attempts to seize weapons—in what these movements believed was an explicit violation of the Second Amendment to the Constitution—but there were also conspiracy fears that the federal government was being manipulated by behind-the-scenes forces or being co-opted by the United Nations, which was seeking to establish a one-world government. Though the patriot and militia movements waned at the turn of the 21st century, they roared back to life with the election of the United States’ first black president. Convinced President Barack Obama was ineligible for the presi- dency due to his alleged country of birth (the so-called Birther argument) and that he was secretly a Muslim who was advancing Islamic causes in the United States, the patriot and militia movements became even more virulent in their antigovern- ment activities and rhetoric. In their contemporary iterations, these movements now spew anti-Semitic vitriol and are viscerally opposed to immigration and gov- ernment programs, such as health care. But even tragedies such as the Columbine shooting have not been contained within their event horizon. Since teenagers Eric Harris and Dylan Klebold killed 12 and injured more than 20 in 1999, more than 50 attacks on schools, or plots to attack schools in a Columbine style, have occurred (Thomas et al. 2014). Among these were the Virginia Tech shooting in 2007, in which student Seung-Hui Cho shot and killed 32 people and injured 17 others, and the Sandy Hook Elemen- tary School shooting, in which 20-year-old Adam Lanza shot and killed 26 peo- ple, including 20 six- and seven-year-olds. The Virginia Tech shooting remains the most deadly mass school shooting in U.S. history. However, the most deadly mass shooting of any kind in the United States occurred on October 1, 2017, when gunman Stephen Paddock opened fire on a music festival in Las Vegas, Nevada. The shooting resulted in 59 deaths and more than 850 injuries (Associ- ated Press 2017). In each of the incidents described in the paragraph above, the discernible event appeared to have been concluded when the killers were either killed or appre- hended. Yet in each of these circumstances, the events spawned “copycat killings,” though these killings may not have occurred until years after the original event. Another interesting facet of these particular extremist events is that none of the killers had apparent political motivations behind their attacks. In almost every circumstance, the killers had emotional and psychological issues that led them to strike out against the innocent. This begs the question, then, are these individuals considered extremists? Certainly in the context of their actions they were extreme in grappling with their emotional problems through violence. They might even be categorized as terrorists if we define a terrorist simply as one who terrorizes. Cer- tainly, in each of the circumstances described above, the emotional, psychological, and physical trauma experienced by the victims of these incidents has lasted far beyond the culmination of the event. Recalling the definition of extremism offered at the beginning of this introduction, the killers in these events perpetrated their acts for neither political nor religious reasons. Yet their heinous actions certainly are extreme by any reasonable definition as there are millions of Americans with mental health issues who do not attack and kill innocents.